#!/usr/bin/python """Main CGI script for web interface""" import base64 import cPickle import cgi import datetime import hmac import sha import simplejson import sys import time import urllib from StringIO import StringIO def revertStandardError(): """Move stderr to stdout, and return the contents of the old stderr.""" errio = sys.stderr if not isinstance(errio, StringIO): return '' sys.stderr = sys.stdout errio.seek(0) return errio.read() def printError(): """Revert stderr to stdout, and print the contents of stderr""" if isinstance(sys.stderr, StringIO): print revertStandardError() if __name__ == '__main__': import atexit atexit.register(printError) import templates from Cheetah.Template import Template import sipb_xen_database from sipb_xen_database import Machine, CDROM, ctx, connect, MachineAccess, Type, Autoinstall import validation import cache_acls from webcommon import InvalidInput, CodeError, State import controls class Checkpoint: def __init__(self): self.start_time = time.time() self.checkpoints = [] def checkpoint(self, s): self.checkpoints.append((s, time.time())) def __str__(self): return ('Timing info:\n%s\n' % '\n'.join(['%s: %s' % (d, t - self.start_time) for (d, t) in self.checkpoints])) checkpoint = Checkpoint() def jquote(string): return "'" + string.replace('\\', '\\\\').replace("'", "\\'").replace('\n', '\\n') + "'" def helppopup(subj): """Return HTML code for a (?) link to a specified help topic""" return ('(?)') def makeErrorPre(old, addition): if addition is None: return if old: return old[:-6] + '\n----\n' + str(addition) + '' else: return '

STDERR:

' + str(addition) + '
' Template.sipb_xen_database = sipb_xen_database Template.helppopup = staticmethod(helppopup) Template.err = None class JsonDict: """Class to store a dictionary that will be converted to JSON""" def __init__(self, **kws): self.data = kws if 'err' in kws: err = kws['err'] del kws['err'] self.addError(err) def __str__(self): return simplejson.dumps(self.data) def addError(self, text): """Add stderr text to be displayed on the website.""" self.data['err'] = \ makeErrorPre(self.data.get('err'), text) class Defaults: """Class to store default values for fields.""" memory = 256 disk = 4.0 cdrom = '' autoinstall = '' name = '' description = '' type = 'linux-hvm' def __init__(self, max_memory=None, max_disk=None, **kws): if max_memory is not None: self.memory = min(self.memory, max_memory) if max_disk is not None: self.max_disk = min(self.disk, max_disk) for key in kws: setattr(self, key, kws[key]) DEFAULT_HEADERS = {'Content-Type': 'text/html'} def invalidInput(op, username, fields, err, emsg): """Print an error page when an InvalidInput exception occurs""" d = dict(op=op, user=username, err_field=err.err_field, err_value=str(err.err_value), stderr=emsg, errorMessage=str(err)) return templates.invalid(searchList=[d]) def hasVnc(status): """Does the machine with a given status list support VNC?""" if status is None: return False for l in status: if l[0] == 'device' and l[1][0] == 'vfb': d = dict(l[1][1:]) return 'location' in d return False def parseCreate(username, state, fields): kws = dict([(kw, fields.getfirst(kw)) for kw in 'name description owner memory disksize vmtype cdrom autoinstall'.split()]) validate = validation.Validate(username, state, strict=True, **kws) return dict(contact=username, name=validate.name, description=validate.description, memory=validate.memory, disksize=validate.disksize, owner=validate.owner, machine_type=validate.vmtype, cdrom=getattr(validate, 'cdrom', None), autoinstall=getattr(validate, 'autoinstall', None)) def create(username, state, fields): """Handler for create requests.""" try: parsed_fields = parseCreate(username, state, fields) machine = controls.createVm(username, state, **parsed_fields) except InvalidInput, err: pass else: err = None state.clear() #Changed global state d = getListDict(username, state) d['err'] = err if err: for field in fields.keys(): setattr(d['defaults'], field, fields.getfirst(field)) else: d['new_machine'] = parsed_fields['name'] return templates.list(searchList=[d]) def getListDict(username, state): """Gets the list of local variables used by list.tmpl.""" checkpoint.checkpoint('Starting') machines = state.machines checkpoint.checkpoint('Got my machines') on = {} has_vnc = {} xmlist = state.xmlist checkpoint.checkpoint('Got uptimes') can_clone = 'ice3' not in state.xmlist_raw for m in machines: if m not in xmlist: has_vnc[m] = 'Off' m.uptime = None else: m.uptime = xmlist[m]['uptime'] if xmlist[m]['console']: has_vnc[m] = True elif m.type.hvm: has_vnc[m] = "WTF?" else: has_vnc[m] = "ParaVM"+helppopup("ParaVM Console") max_memory = validation.maxMemory(username, state) max_disk = validation.maxDisk(username) checkpoint.checkpoint('Got max mem/disk') defaults = Defaults(max_memory=max_memory, max_disk=max_disk, owner=username, cdrom='gutsy-i386') checkpoint.checkpoint('Got defaults') def sortkey(machine): return (machine.owner != username, machine.owner, machine.name) machines = sorted(machines, key=sortkey) d = dict(user=username, cant_add_vm=validation.cantAddVm(username, state), max_memory=max_memory, max_disk=max_disk, defaults=defaults, machines=machines, has_vnc=has_vnc, can_clone=can_clone) return d def listVms(username, state, fields): """Handler for list requests.""" checkpoint.checkpoint('Getting list dict') d = getListDict(username, state) checkpoint.checkpoint('Got list dict') return templates.list(searchList=[d]) def vnc(username, state, fields): """VNC applet page. Note that due to same-domain restrictions, the applet connects to the webserver, which needs to forward those requests to the xen server. The Xen server runs another proxy that (1) authenticates and (2) finds the correct port for the VM. You might want iptables like: -t nat -A PREROUTING -s ! 18.181.0.60 -i eth1 -p tcp -m tcp \ --dport 10003 -j DNAT --to-destination 18.181.0.60:10003 -t nat -A POSTROUTING -d 18.181.0.60 -o eth1 -p tcp -m tcp \ --dport 10003 -j SNAT --to-source 18.187.7.142 -A FORWARD -d 18.181.0.60 -i eth1 -o eth1 -p tcp -m tcp \ --dport 10003 -j ACCEPT Remember to enable iptables! echo 1 > /proc/sys/net/ipv4/ip_forward """ machine = validation.Validate(username, state, machine_id=fields.getfirst('machine_id')).machine TOKEN_KEY = "0M6W0U1IXexThi5idy8mnkqPKEq1LtEnlK/pZSn0cDrN" data = {} data["user"] = username data["machine"] = machine.name data["expires"] = time.time()+(5*60) pickled_data = cPickle.dumps(data) m = hmac.new(TOKEN_KEY, digestmod=sha) m.update(pickled_data) token = {'data': pickled_data, 'digest': m.digest()} token = cPickle.dumps(token) token = base64.urlsafe_b64encode(token) status = controls.statusInfo(machine) has_vnc = hasVnc(status) d = dict(user=username, on=status, has_vnc=has_vnc, machine=machine, hostname=state.environ.get('SERVER_NAME', 'localhost'), authtoken=token) return templates.vnc(searchList=[d]) def getHostname(nic): """Find the hostname associated with a NIC. XXX this should be merged with the similar logic in DNS and DHCP. """ if nic.hostname and '.' in nic.hostname: return nic.hostname elif nic.machine: return nic.machine.name + '.xvm.mit.edu' else: return None def getNicInfo(data_dict, machine): """Helper function for info, get data on nics for a machine. Modifies data_dict to include the relevant data, and returns a list of (key, name) pairs to display "name: data_dict[key]" to the user. """ data_dict['num_nics'] = len(machine.nics) nic_fields_template = [('nic%s_hostname', 'NIC %s Hostname'), ('nic%s_mac', 'NIC %s MAC Addr'), ('nic%s_ip', 'NIC %s IP'), ] nic_fields = [] for i in range(len(machine.nics)): nic_fields.extend([(x % i, y % i) for x, y in nic_fields_template]) if not i: data_dict['nic%s_hostname' % i] = getHostname(machine.nics[i]) data_dict['nic%s_mac' % i] = machine.nics[i].mac_addr data_dict['nic%s_ip' % i] = machine.nics[i].ip if len(machine.nics) == 1: nic_fields = [(x, y.replace('NIC 0 ', '')) for x, y in nic_fields] return nic_fields def getDiskInfo(data_dict, machine): """Helper function for info, get data on disks for a machine. Modifies data_dict to include the relevant data, and returns a list of (key, name) pairs to display "name: data_dict[key]" to the user. """ data_dict['num_disks'] = len(machine.disks) disk_fields_template = [('%s_size', '%s size')] disk_fields = [] for disk in machine.disks: name = disk.guest_device_name disk_fields.extend([(x % name, y % name) for x, y in disk_fields_template]) data_dict['%s_size' % name] = "%0.1f GiB" % (disk.size / 1024.) return disk_fields def command(username, state, fields): """Handler for running commands like boot and delete on a VM.""" back = fields.getfirst('back') try: d = controls.commandResult(username, state, fields) if d['command'] == 'Delete VM': back = 'list' except InvalidInput, err: if not back: raise print >> sys.stderr, err result = err else: result = 'Success!' if not back: return templates.command(searchList=[d]) if back == 'list': state.clear() #Changed global state d = getListDict(username, state) d['result'] = result return templates.list(searchList=[d]) elif back == 'info': machine = validation.Validate(username, state, machine_id=fields.getfirst('machine_id')).machine return ({'Status': '303 See Other', 'Location': '/info?machine_id=%d' % machine.machine_id}, "You shouldn't see this message.") else: raise InvalidInput('back', back, 'Not a known back page.') def modifyDict(username, state, fields): """Modify a machine as specified by CGI arguments. Return a list of local variables for modify.tmpl. """ olddisk = {} transaction = ctx.current.create_transaction() try: kws = dict([(kw, fields.getfirst(kw)) for kw in 'machine_id owner admin contact name description memory vmtype disksize'.split()]) validate = validation.Validate(username, state, **kws) machine = validate.machine oldname = machine.name if hasattr(validate, 'memory'): machine.memory = validate.memory if hasattr(validate, 'vmtype'): machine.type = validate.vmtype if hasattr(validate, 'disksize'): disksize = validate.disksize disk = machine.disks[0] if disk.size != disksize: olddisk[disk.guest_device_name] = disksize disk.size = disksize ctx.current.save(disk) update_acl = False if hasattr(validate, 'owner') and validate.owner != machine.owner: machine.owner = validate.owner update_acl = True if hasattr(validate, 'name'): machine.name = validate.name if hasattr(validate, 'description'): machine.description = validate.description if hasattr(validate, 'admin') and validate.admin != machine.administrator: machine.administrator = validate.admin update_acl = True if hasattr(validate, 'contact'): machine.contact = validate.contact ctx.current.save(machine) if update_acl: print >> sys.stderr, machine, machine.administrator cache_acls.refreshMachine(machine) transaction.commit() except: transaction.rollback() raise for diskname in olddisk: controls.resizeDisk(oldname, diskname, str(olddisk[diskname])) if hasattr(validate, 'name'): controls.renameMachine(machine, oldname, validate.name) return dict(user=username, command="modify", machine=machine) def modify(username, state, fields): """Handler for modifying attributes of a machine.""" try: modify_dict = modifyDict(username, state, fields) except InvalidInput, err: result = None machine = validation.Validate(username, state, machine_id=fields.getfirst('machine_id')).machine else: machine = modify_dict['machine'] result = 'Success!' err = None info_dict = infoDict(username, state, machine) info_dict['err'] = err if err: for field in fields.keys(): setattr(info_dict['defaults'], field, fields.getfirst(field)) info_dict['result'] = result return templates.info(searchList=[info_dict]) def helpHandler(username, state, fields): """Handler for help messages.""" simple = fields.getfirst('simple') subjects = fields.getlist('subject') help_mapping = {'ParaVM Console': """ ParaVM machines do not support local console access over VNC. To access the serial console of these machines, you can SSH with Kerberos to console.xvm.mit.edu, using the name of the machine as your username.""", 'HVM/ParaVM': """ HVM machines use the virtualization features of the processor, while ParaVM machines use Xen's emulation of virtualization features. You want an HVM virtualized machine.""", 'CPU Weight': """ Don't ask us! We're as mystified as you are.""", 'Owner': """ The owner field is used to determine quotas. It must be the name of a locker that you are an AFS administrator of. In particular, you or an AFS group you are a member of must have AFS rlidwka bits on the locker. You can check who administers the LOCKER locker using the commands 'attach LOCKER; fs la /mit/LOCKER' on Athena.) See also administrator.""", 'Administrator': """ The administrator field determines who can access the console and power on and off the machine. This can be either a user or a moira group.""", 'Quotas': """ Quotas are determined on a per-locker basis. Each locker may have a maximum of 512 megabytes of active ram, 50 gigabytes of disk, and 4 active machines.""", 'Console': """ Framebuffer: At a Linux boot prompt in your VM, try setting fb=false to disable the framebuffer. If you don't, your machine will run just fine, but the applet's display of the console will suffer artifacts. """ } if not subjects: subjects = sorted(help_mapping.keys()) d = dict(user=username, simple=simple, subjects=subjects, mapping=help_mapping) return templates.help(searchList=[d]) def badOperation(u, s, e): """Function called when accessing an unknown URI.""" return ({'Status': '404 Not Found'}, 'Invalid operation.') def infoDict(username, state, machine): """Get the variables used by info.tmpl.""" status = controls.statusInfo(machine) checkpoint.checkpoint('Getting status info') has_vnc = hasVnc(status) if status is None: main_status = dict(name=machine.name, memory=str(machine.memory)) uptime = None cputime = None else: main_status = dict(status[1:]) start_time = float(main_status.get('start_time', 0)) uptime = datetime.timedelta(seconds=int(time.time()-start_time)) cpu_time_float = float(main_status.get('cpu_time', 0)) cputime = datetime.timedelta(seconds=int(cpu_time_float)) checkpoint.checkpoint('Status') display_fields = """name uptime memory state cpu_weight on_reboot on_poweroff on_crash on_xend_start on_xend_stop bootloader""".split() display_fields = [('name', 'Name'), ('description', 'Description'), ('owner', 'Owner'), ('administrator', 'Administrator'), ('contact', 'Contact'), ('type', 'Type'), 'NIC_INFO', ('uptime', 'uptime'), ('cputime', 'CPU usage'), ('memory', 'RAM'), 'DISK_INFO', ('state', 'state (xen format)'), ('cpu_weight', 'CPU weight'+helppopup('CPU Weight')), ('on_reboot', 'Action on VM reboot'), ('on_poweroff', 'Action on VM poweroff'), ('on_crash', 'Action on VM crash'), ('on_xend_start', 'Action on Xen start'), ('on_xend_stop', 'Action on Xen stop'), ('bootloader', 'Bootloader options'), ] fields = [] machine_info = {} machine_info['name'] = machine.name machine_info['description'] = machine.description machine_info['type'] = machine.type.hvm and 'HVM' or 'ParaVM' machine_info['owner'] = machine.owner machine_info['administrator'] = machine.administrator machine_info['contact'] = machine.contact nic_fields = getNicInfo(machine_info, machine) nic_point = display_fields.index('NIC_INFO') display_fields = (display_fields[:nic_point] + nic_fields + display_fields[nic_point+1:]) disk_fields = getDiskInfo(machine_info, machine) disk_point = display_fields.index('DISK_INFO') display_fields = (display_fields[:disk_point] + disk_fields + display_fields[disk_point+1:]) main_status['memory'] += ' MiB' for field, disp in display_fields: if field in ('uptime', 'cputime') and locals()[field] is not None: fields.append((disp, locals()[field])) elif field in machine_info: fields.append((disp, machine_info[field])) elif field in main_status: fields.append((disp, main_status[field])) else: pass #fields.append((disp, None)) checkpoint.checkpoint('Got fields') max_mem = validation.maxMemory(machine.owner, state, machine, False) checkpoint.checkpoint('Got mem') max_disk = validation.maxDisk(machine.owner, machine) defaults = Defaults() for name in 'machine_id name description administrator owner memory contact'.split(): setattr(defaults, name, getattr(machine, name)) defaults.type = machine.type.type_id defaults.disk = "%0.2f" % (machine.disks[0].size/1024.) checkpoint.checkpoint('Got defaults') d = dict(user=username, on=status is not None, machine=machine, defaults=defaults, has_vnc=has_vnc, uptime=str(uptime), ram=machine.memory, max_mem=max_mem, max_disk=max_disk, owner_help=helppopup("Owner"), fields = fields) return d def info(username, state, fields): """Handler for info on a single VM.""" machine = validation.Validate(username, state, machine_id=fields.getfirst('machine_id')).machine d = infoDict(username, state, machine) checkpoint.checkpoint('Got infodict') return templates.info(searchList=[d]) def unauthFront(_, _2, fields): """Information for unauth'd users.""" return templates.unauth(searchList=[{'simple' : True}]) def throwError(_, __, ___): """Throw an error, to test the error-tracing mechanisms.""" raise RuntimeError("test of the emergency broadcast system") mapping = dict(list=listVms, vnc=vnc, command=command, modify=modify, info=info, create=create, help=helpHandler, unauth=unauthFront, errortest=throwError) def printHeaders(headers): """Print a dictionary as HTTP headers.""" for key, value in headers.iteritems(): print '%s: %s' % (key, value) print def send_error_mail(subject, body): import subprocess to = 'xvm@mit.edu' mail = """To: %s From: root@xvm.mit.edu Subject: %s %s """ % (to, subject, body) p = subprocess.Popen(['/usr/sbin/sendmail', to], stdin=subprocess.PIPE) p.stdin.write(mail) p.stdin.close() p.wait() def show_error(op, username, fields, err, emsg, traceback): """Print an error page when an exception occurs""" d = dict(op=op, user=username, fields=fields, errorMessage=str(err), stderr=emsg, traceback=traceback) details = templates.error_raw(searchList=[d]) if username not in ('price', 'ecprice', 'andersk'): #add yourself at will send_error_mail('xvm error on %s for %s: %s' % (op, username, err), details) d['details'] = details return templates.error(searchList=[d]) def getUser(environ): """Return the current user based on the SSL environment variables""" return environ.get('REMOTE_USER', None) class App: def __init__(self, environ, start_response): self.environ = environ self.start = start_response self.username = getUser(environ) self.state = State(self.username) self.state.environ = environ def __iter__(self): sipb_xen_database.clear_cache() sys.stderr = StringIO() fields = cgi.FieldStorage(fp=self.environ['wsgi.input'], environ=self.environ) operation = self.environ.get('PATH_INFO', '') if not operation: self.start("301 Moved Permanently", [('Location', self.environ['SCRIPT_NAME']+'/')]) return if self.username is None: operation = 'unauth' if operation.startswith('/'): operation = operation[1:] if not operation: operation = 'list' print 'Starting', operation start_time = time.time() fun = mapping.get(operation, badOperation) try: checkpoint.checkpoint('Before') output = fun(self.username, self.state, fields) checkpoint.checkpoint('After') headers = dict(DEFAULT_HEADERS) if isinstance(output, tuple): new_headers, output = output headers.update(new_headers) e = revertStandardError() if e: if isinstance(output, basestring): sys.stderr = StringIO() x = str(output) print >> sys.stderr, x print >> sys.stderr, 'XXX' print >> sys.stderr, e raise Exception() output.addError(e) output_string = str(output) checkpoint.checkpoint('output as a string') except Exception, err: if not fields.has_key('js'): if isinstance(err, InvalidInput): self.start('200 OK', [('Content-Type', 'text/html')]) e = revertStandardError() yield str(invalidInput(operation, self.username, fields, err, e)) return import traceback self.start('500 Internal Server Error', [('Content-Type', 'text/html')]) e = revertStandardError() s = show_error(operation, self.username, fields, err, e, traceback.format_exc()) yield str(s) return status = headers.setdefault('Status', '200 OK') del headers['Status'] self.start(status, headers.items()) yield output_string if fields.has_key('timedebug'): yield '
%s
' % cgi.escape(str(checkpoint)) def constructor(): connect('postgres://sipb-xen@sipb-xen-dev.mit.edu/sipb_xen') return App def main(): from flup.server.fcgi_fork import WSGIServer WSGIServer(constructor()).run() if __name__ == '__main__': main()